Many on-line or web-based applications and services rely partially, and in some cases almost entirely, on user-generated content—that is, content generated by the end-users of the particular application or service. The success of such applications and services is heavily dependent upon the ability to attract and retain users who are willing to participate by generating content that is to be shared with other users. One particular type of application or service for which this holds true is an on-line question-and-answer service. In general, a question-and-answer service is a service that allows its end-users to post questions, post answers to questions, or simply browse the questions and answers that others have posted. From the perspective of its users, the usefulness of a question-and-answer service or application depends significantly on the extent to which meaningful answers are provided to the questions being posted.